Attachment for vacuum tubes



July 18, 1933. 5 K 1,918,863

ATTACHMENT FOR VACUUM TUBES Filed Aug. 2, 1929 JELL.

INVENTOR.

ATTORNEYS.

Herschel EPack.

l atenhfl July 118, 1933 PATENT OFFICE.

HERSCHEL G. PACK, OF SAN FRANCISCO, CALIFORNIA ATTACHMENT FOB VACUUM TUBES Application filed August 2, 1929. Serial No. 383,018.

The present invention relates to attachments for vacuum tubes such as employed in radio and otherelectrical apparatus, and having base contact prongs releasably engageis; able with contact members in a socket for connecting the elements of the tube in electric circuit.

The primary object of the inventlon is to provide a device for attachment to vacuum tubes whereby electrical connection may be made to the base prongs of the tube thru means other than those provided for by the radio or other electrical apparatus in which the tube is used,

A further object of the invention is to provide an attachment for vacuum tubes providing a simple and 'efficient means whereby electrical connection to the elements of the tube and the circuits connected thereto may be obtained without disturbing the permanent electrical connections of the apparatus,

A. further object of the invention is to provide an attachment adapted to be removably associated with the baseprongs'of a vacuum tube in a manner whereby electrical energy applied to the tube may be tapped for external use. v I 1 A further object of the invention is to provide an attachment of this character which when applied to the base of a vacuum tube in electrical connection with the base prongs thereof will not elevate the tube above its supporting socket to an objectionable extent and thereby permitting use of he attachment upon tubes mounted in cabinets or in other apparatus having but little clearance above the tube. I

Briefly, the invention resides in the provision of an attachment adapted to be slipped over the base prongs of a vacuum tube where-' by additional plate, grid or filament voltages may be applied to the tube, changes or additions may be madeto the circuits connected with the tube, and microphones, phonograph pick-ups and similar apparatus may be connected in the apparatus without dis-' turbing the permanent electrical connections to the tube sockets.

Other objects and advantages of the inment for use with vention will be apparent during the course of the following-"detailed description, taken in connection with the accompanying drawing forming a part of this specification and in which drawing: I

Figure 1 is a sectional view thru the attachment shown applied to a vacuum tube andshowing the tube in position in' a conventional type of socket having electrical connection with the base prongs of the tube;

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Figure 2 is a perspective view showing the attachment applied to the base ofavacuum tube. V i I Figure 3 is aftopplan view of theattachinentu I Figure 4 is a bottom plan tachment.

Figure 5 is an enlarged fragmentary plan view of one of the spring contacts.

Figure 6 is a top plan view of .view of the at-- an attach- Vacuum tubes having five base prongs. p p I I Q In the drawing, and wherein similar refer ence characters designate corresponding parts thruout the several v iew s,"the letter A designatesa vacuum tube of conventional construction, B a socket for removably receiving the tube A, and C the connector attachment for removable connection with the lower end of the tube A.. I

The tube A includes the base 5 provided with the usualfcontact prongs 6 projecting from the bottom flat side of the base for insertion into the socket B. The socket'B which is of ordinary construction includes the insulating base? of substantially fiat formationand provided about its axial center with openings 8v tor (iii receiving the prongs 6 ofthe tube A. a Mount-' in the socket is insured by forming certain of the contact prongs 6 of greater diameter ber 15 supports a series of metallic-contact strips 18 which may be formed of spring brass or phosphor bronze, and one of the strips is provided for each contact prong of the tube with which the connector is adapted to be associated.

These contact strips 1 8are of substantially Z formation including flatbase portions 19 having upstanding portions 20at their outer ends from the upperends of which are outturned attaching portions 21 for contact with the under surface of the su ortin member 15. The flat base portions19 are all dis posed in a like plane and extend in a radial direction with respect to the circular opening 16. Adjacent the inner end, of, each flat base or contact portion 19 is provided a prong receiving opening 22 provided with radiallyextending slots 23permitting slight yielding of the metal about the opening for frictionally receiving the tube prongs 6.

The upper outturned attaching portions 21 of the contact strips are apertured to receive the sets of threadedbolts 24 which project upwardly thru the shanks of head-member 15 and have threaded thereon binding nuts 25. Above the nuts 25 are knurled nuts 26 threaded upon the'bolts 24. These bolts 24, nuts 25 and 26 aside from connecting the contact strips in insulated relation upon the supportingmember- 15 also form terminals for connecting conductors to the independent contact strips 18 at a location above the supporting member 15.

In attaching the device to the base of the tube A the tube is first removed from the socket and the. connector slipped over the base 5 with the prongs 6v passing thru the openings 22 in the flat base portions of the contact strips 18. The tubefmay then be in serted in the socket Band it will be observed that the tube will only be elevated for the thickness of the contact strips 18 which are now disposedbetween the tube base 5 and socket B in'electrical contact with the base prongs 6. By observing Figures 1 and 2 it will be seen that the Z formation of the 0011- tact strips elevates the terminals or binding posts 30 a substantial distance above the socket B and out of possible electrical contact with any metallic portions thereof. Thus 'will be seen that a conductor connected to one of the binding posts 30 will have electrical contact with one of the tube prongs 6 thru its associated contact strip.

When the .connector attachment is applied to the tube base and the tube inserted in the socket it will be seen that electrical connection to the elements of the tube and a circuit connected thereto may be readily and efiiciently made thru attachment of conductors to the binding posts 30 and without disturbmg the permanent electrical connection of conductors to the soldering strips 12 of the contact members 10.

In the commercial built radio receiving sets and in various other types of electrical apparatus employing vacuum tubes, very little clearance is provided above the tubes and with the type of attachment shown it will be seen thatltheheight of the tube above the base is increased only a small amount and thus permits use of the attachment without alteration to the apparatus.

From the foregoing it Will be apparent that a novel and improved construction for a device of this character has been provided which willhave an unlimited number of uses for making electrical connection to the elements of the vacuum tubes in various types of electrical apparatus without disturbing permanent electrical connection to the socket of the tube. i i

In Figure 6, the socket 'B has been shown with the supporting member or ring 15 provided with five of the contact members 18 each provided with an independent binding post 30. This form of connector is primarily intended for use with a vacum tube having five base prongs.

Changes in detail may be made to the form.

of invention herein shown and described, without departing from the spirit of the invention or the scopeof the following claims. I claim: l

1. A tapping connector attachment for vacuum tubes comprising a supporting mem-' ber having an opening therethru for r'eceiving the base of the tube, independent contact strips'extending below the supporting member and having inturned fiat lower end portiouns for engaging flat upon the lower end of thetube base and apertured to receive therethru the contact prongs of the tube, and a binding post connecting the up per end of each contact strip to the supporting member.

2. A tapping connector attachment for vaccum tubes having contact prongs insertableinto a flat top socket,.comprising a supporting member having an opening therethru for receiving the base ofthe tube, a series of independent contact strips having flat base portions arranged in a like plane for receiving the contact prongs of the tube therethru,

an upturned portion at the outer end of each base portion, and an outturned attaching portion at the upper end of each upturned portion, and combined attaching and binding posts connecting the outturned ends of the contact strips to the underside of thesupand an outturned apertured attaching portion at the upper end of each upturned portion, said flat base portions being arranged in radial relation and in a like p-lane and having prong receiving openings adjacent their inner ends, an attaching bolt connecting the outturned upper end of each contact strip to the underside of the supporting member and, having threaded shank portions projecting above the upper surface of the supporting member, a binding nut threaded on each bolt at the upperside, of the supporting member,

and a clamping nut threaded uponthe upper 7 end of each bolt for electrically connecting conductors to the contact strips for electrical connection with the contact prongs of the tube. V

HERSCHEL on PACK. 

